First, let me introduce myself. I am new to the board and nissans in general. My family and I have been racing hondas and subarus for about 4 years, but finally decided to upgrade to something a little more sophisticated to contest the Grand-Am GS category. The choice was a Z, specifically, one of the Unitech/Performance Nissans. This car has a great pedigree, including a class win while being shoed by none other than Boris Said.

But anyway, on our way to pick up the car, we found out that the seller had taken it to the track one more time to say his goodbyes, and quote "popped the motor". That's cool, it was an old motor and we already had a replacement on it's way from NISMO. He graciously lowered the price and we picked up our car. (what a car too, excellent build quality).

The motor came out last week, and it didn't show any signs of what had happened, at least, none we saw. Then last night we start to take it apart to determine cause of failure:

Looks like any engine...


Hmm, don't like the look of this crack behind the oil filter...


Or this huge hole behind the crank pulley. Is the crank at an angle?


So lets pop off the oil pan and see what we got... AAARGH!!




Wow, this was total destruction...




On the plus side, the Grand-Am spec cam and spring kit was still perfect, as were the heads. One slightly bent valve needs to be replaced. Once we get a new short block, we can have a nice spare.

You'll see this car out in new livery at Grand-Am events starting in April. No pics yet, it's at the paint shop. Enjoys the pics!

 

Nice write-up and welcome to the board!

 

... How did you get a replacement motor from "Nismo"? I didn't know they sold complete engines.

 

Welcome to the boards. Looking forward to seeing the Z!

 

I think he is trying to say a replacement OE motor from Nissan Motorsports USA. Its where all us racers get our spare parts from.

 

What the heck did they do to snap the crank in half?

 

Chris, I hope they lowered the price a lot, because balancing and blueprinting those motors is not cheap. To be competitive you wont be able to just swap out the cams and valvetrain kit into your new OE motor, you will need to send the motor to a good engine builder to have everything blueprinted, balanced, port and polished. Figure $10-15k.

 

To correct myself, I did mean Nissan Motorsports USA. We have 2 new OE motors and an extra GA spec valve train kit that will be here on monday. One of the motors is going straight into the car with the cams we pull off this motor and will be used as a test engine when we sort the chassis in march. The second motor is going to our motor builder for a blueprint/balance. When we get to Homestead in April, that motor will be in the car, and the test motor will be along as a spare while we build a third engine.

This unitec motor had balanced internals down to the crank, but the head was untooled. Beyond special allowance for valve train mods, you cannot modify the head in any way for Grand-Am GS. Saves teams a little bit of money anyway. It is nice to be able to actually work on the motor. We are not allowed to touch anything in our Legacy.

 

eh, you can repair all that

 

Sure. That's what JB Weld is for!

 

Hello Chris - fancy finding you here today. In your repair of the engine, don't underestimate the strength of Super Glue and/or duct tape either...

 

Scott! You own a Z! Small world. I think you would really enjoy being in our paddock this year...

 

It looks like you lost a connecting rod which may have been caused by bad rod bolts or broken bearing. That caused the crank to break. Balance and blue print shouldnt be much over $5k at a good engine shop. Welcome to the world of Z racing. If you ever need a co-driver for any races I know where you can find one who has raced at over 25 tracks in the USA.

 

Thanks for the welcome. We are in fact looking for co-drivers for this season. Have him contact me.

 

Welcome to the boards. I hope you got their adjustable front A arms, that use the shims to put in and take out camber. They are a very nifty item and not made anywhere anymore. Jackson builds a nice car.

 

You are allowed to balance and blueprint the heads and bottom end, along with match porting and polishing. Also, if the OE manufacture offers oversize pistons for engine rebuilds, you are allowed to go to the second oversize piston from stock. Talking with BJ, their motors were being built by Menards Engineering, I thought he said they cost close $15k.

I know one of the engine builders who does a lot of the M3 motors, they do some serious machine work and use stiffer valve springs etc, those motors cost close to $20k to build! (But they are also putting out close to 400hp)

 

A 'popped' motor is a common experience in racing. Unfortunately, I've had as much "experience" as any! I'd also suggest you magnaflux ANY drivetrain pieces (including cams) that you plan on reusing off that motor. With all the damage your photos show, I'd also consider going through and replumbing ALL the oil lines and replacing the coolers as well. There's shrapnel in there that ONLY comes loose when the engine comes up to temp and works its way into your new bullet.

Probably preaching to the choir- but don't throw good money after bad. Best of luck in your Grand-Am effort!

David Muramoto
Senior Editor
Nissan Sport Magazine

 

Ouch!

Speaking of engine failures - does the VQ35 come with any stock baffles in the oil pan?

With race tires and high g loading, perhaps the engine had some oil starvation?

 

Naw. Accusump.

I think the real reason was 2 seasons of hard racing. Every motor has it's date with destiny, no matter how expensive or well built.

 

Absolutely. Those cars were campaigned hard on the Performance Nissan Team out of Duarte, and tested and tuned out at the big track at Willow Springs International Raceway in the Mojave, out in Rosamond near Edwards AFB. They were not made to go 20,000 miles.

+1 for Dave's comment above. The system should be assumed to have bad stuff everywhere, and then some.

Have fun with it, and let us know when you bring her out to the track!

Was this the 32 or 33 car? Are you keeping it Silver?